Providing new and more energy efficient illumination devices is one of the important technical challenges which society and industry faces. Basing lighting devices on Light Emitting Diodes (LEDs) which provide more light per unit of energy is a common solution. Hence, the reduced driving cost and improved performance of LEDs enable their use for general illumination. However, to reach widespread mass market proliferation of new lighting devices it is also desirable to reduce the manufacturing costs. Especially for lighting devices designed as retrofits for current lighting devices, such as incandescent bulbs and tube lighting. Retrofitable lighting devices using LEDs are currently available to the public, however the prices of such devices are often times much larger than they are for traditional lighting devices, hence the general public might still be more inclined to buy a traditional lighting device.
Thus there is a need to reduce the costs for lighting devices using LEDs to make them more available. One way to reduce the costs is to reduce the Bill Of Material (BOM), another way is to reduce the number of steps or tools required during manufacturing. US patent application 2011/0235321 for example, discloses a lighting device having a roll formed heat sink for an LED fixture, and the roll formed heat sink is then slidably inserted into an extruded light transmitting cover which will enclose the LEDs. However, the step of inserting the heat sink and LEDs into a light transmitting cover will require an additional step and further need a spacious assembly area. Further, each component need to be manipulated separately, e.g. placed or positioned, which will take time and consideration during manufacture.